Tire mold cleaning method and apparatus

ABSTRACT

A method and apparatus for cleaning a tire mold with frozen CO 2  cleaning material wherein a portable frame is positioned on a bottom mold of a tire press and has a rotatable frame on which a nozzle support is mounted for swivel action to clean the upper mold half and the lower mold half as the nozzle support is moved radially and circumferentially of the tire mold.

TECHNICAL FIELD

This invention relates to tire mold cleaning and especially to automatedsidewall cleaning of the tire mold halves without removing the moldhalves from the tire press.

BACKGROUND ART

Tire mold cleaning apparatus such as that shown in U.S. Pat. No.3,905,155 have been designed for cleaning a tire mold while in the presswith an abrasive such as glass beads. One of the problems with this typeof cleaner is the removal of the spent abrasive from the tire mold. Ithas been proposed to use frozen CO2 as the abrasive which leaves noresidue. With the CO2 cleaning a high noise level is created requiring asound curtain to be placed around the mold. Enclosures for the moldwhich are soundproof have been proposed, however, this requires removingthe mold from the tire press. The mold cleaner also needs to clean theupper and lower mold halves without removing either of these mold halvesfrom the tire press. This creates a problem in adapting the cleaningapparatus to maintain the spray nozzle at a constant distance from themold surface while adjusting the position of the spray nozzle todifferent spacing between the mold halves depending upon the size of thetire press.

SUMMARY OF THE INVENTION

The present invention is directed to a portable tire mold cleaningapparatus for cleaning the sidewall forming surface of the mold withfrozen CO2 without removing the mold from the tire press. The moldcleaning apparatus may be transported to the tire press and quickly setup in the breech ring of the press. The spray nozzle is rotated andmoved radially as well as axially to follow the contour of the mold. Thenozzle is mounted for rotation on a horizontal shaft and can be swiveledfrom a down position for cleaning the lower mold half to an upperposition for cleaning the upper mold half.

In accordance with one aspect of the invention there is provided acleaning apparatus for cleaning a tire mold mounted in a tire press, thetire press having an upper mold half positioned over a lower mold halfand movable vertically to open and close the mold characterized by:

(a) a supporting frame for mounting over said lower mold half and underthe upper mold half;

(b) a rotatable frame mounted on the supporting frame for rotation abouta horizontal axis;

(c) a nozzle for spraying a cleaning material on mold surfaces of theupper mold half and the lower mold half mounted on a control armsupported on the rotatable frame;

(d) means to rotate the rotatable frame about the horizontal axis tomove the control arm from a down position for spraying the cleaningmaterial on the lower mold half to an up position for spraying thecleaning material on the upper mold half; and,

(e) means to traverse the control arm circumferentially of the tire moldabout a vertical mold axis with the rotatable frame in the down positionand in the up position.

In accordance with another aspect of the invention, there is provided amethod of cleaning a tire mold having an upper mold half positioned overa lower mold half and movable vertically to open and close said moldwith a portable cleaning apparatus having a supporting frame, arotatable frame mounted on the supporting frame, a nozzle for sprayingcleaning material mounted on a control arm supported on the rotatableframe and in communication with a source of cleaning materialcharacterized by the steps of:

(a) mounting the supporting frame over the lower mold half;

(b) rotating the rotatable frame to a position with the control arm inan up position wherein the nozzle in directed at a mold surface of theupper mold half;

(c) communicating cleaning material to a nozzle to project the materialagainst the mold surface of the upper mold half;

(d) traversing the nozzle circumferentially of the upper mold half onthe control arm for cleaning the mold surface of the upper mold half;

(e) rotating the rotatable frame to a position with the control arm in adown position wherein the nozzle is directed at a mold surface of thelower mold half;

(f) traversing the nozzle circumferentially of the lower mold half onthe control arm for cleaning the mold surface of the lower mold half;and,

(g) removing the supporting frame from the lower mold half.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of the portable cleaning apparatus embodying theinvention before mounting in a tire press.

FIG. 2 is a front elevation of the apparatus of FIG. 1 mounted in a tirepress taken along line 2—2 in FIG. 1 showing the nozzle in position forcleaning the lower mold half with parts broken away to show the nozzle.

FIG. 3 is a side view of the apparatus of FIG. 1 taken along line 3—3 inFIG. 1 showing the nozzle in position for cleaning the lower mold halfshown in cross section and with parts broken away.

FIG. 4 is a side view like FIG. 3 showing the nozzle in position forcleaning the upper mold half which is shown in cross section. Theposition of the sound curtain is also shown in dotted lines

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a portable mold cleaning apparatus 10 is shownprior to mounting in a tire press 12. In FIG. 2, the apparatus 10 isshown mounted in a lower mold 16. The apparatus 10 has a supportingframe 18 with a cylindrical rolled angle iron base 20, having a diameterfor seating in a press breech ring 21. Mounted on the base 20 areadjustable stabilizer legs 22 and side leg assemblies 23. Pillow blockbearings 24 and 26 are supported on the side leg assemblies 23 andratchets 28 and 30 are provided for adjusting the height of the frame18. A shaft 36 extends through the bearings 24 and 26 from one side ofthe lower mold half 16 to a rotatable frame 40 and then to the otherside where a crank 38 is mounted for tuning the shaft. The rotatableframe 40 supports a frozen CO2 cleaning unit 42.

Referring to FIGS. 2, 3 and 4, a manifold 44 is mounted on the rotatableframe 40. The upper mold half 14 is positioned directly over the lowermold half 16. A hub 46 is rotatably mounted on the manifold 44 andconnected to a pulley 48 which is driven by a belt 50 trained around apulley 51 having a shaft driven by a motor 52 which may be mounted onthe rotatable, frame 40.

A supporting arm 59 is mounted on the hub 46 and supports a stabilizerbracket 60 having guide rollers 62 for engaging the sides of slot 64 ina control arm 66 which supports a nozzle 68. An upper end 70 of thecontrol arm 66 has a cam roller 72 rotatably supported in a cam slot 74of a depth gauge 76 fastened to the supporting arm 59.

A rodless cylinder 78 is mounted on the supporting arm 59 and has apiston member 80 connected to the stabilizer bracket 60 for moving thestabilizer bracket and the control arm 66 in a radial direction acrossthe mold surface so that the cam slot 74 and the cam roller 72 controlthe movement of the nozzle 68 at positions spaced from the mold surfaceand which conform with the contour of a mold surface 81 of the lowermold half 16 and the contour of a mold surface 85 of the upper mold half14.

In addition to controlling the position of the nozzle 68 across thewidth of the mold cavity 81 in the lower mold half 16, the position ofthe nozzle circumferentially of the mold is provided by the motor 52which rotates the drive pulley 51, causing the belt 50 to rotate thepulley 48 and traverse the nozzle 68 around the circumference of thelower mold half 16. A rotary union 84 may be mounted on the hub 46 andsupports a connecting hose 87 in communication with a source of cleaningmaterial such as frozen CO2 . Bearings 89 and 90 at the ends of the hub46 permit rotation of the hub relative to the manifold 44 and the rotaryunion 84.

In operation, as shown in FIG. 4, the cleaning process begins at theoutside diameter of an upper mold half 14 of the press 12. The uppermold cavity may then be cleaned by projecting the CO2 and air throughthe nozzle 68, controlling the rotation of the nozzle by regulating thespeed of the DC motor 52 and regulating the movement of the nozzle 68across the mold cavity 21 by controlling the movement of the rodlesscylinder 78. After the nozzle 68 makes one revolution, it makes contactwith a proximity switch, which activates the rodless cylinder 78 causingthe nozzle 68 to move inwardly approximately 0.46 inches (1.17 cm). Whenthe nozzle 68 moves inwardly, it follows the cam slot 74, which iscontoured to the shape of the mold cavity 85. This maintains equalpressure and nozzle spray width on the surface of the mold cavity 85 atall times. When the nozzle 68 reaches the inside diameter of the uppermold half 14 it trips another proximity switch which ends the cycle. Atthis point, the nozzle 68 will no longer be indexed inwardly; however,it will continue to revolve until the motor 52 is turned off. Thepurpose of keeping the motor 52 running is to allow the CO2 lines to beblown clear, and avoid projecting frozen CO2 on one spot. Suitablecontrols may be provided to regulate the speed of the motor 52 forrotating the hub 46 at a desired speed. These controls may also becoordinated is with the controls for the rodless cylinder 78 to providethe desired travel of the nozzle 68 radially across the lower moldsurface 81 of the lower mold half 16 and the mold surface of the uppermold cavity 85. Once the cycle is completed and the upper mold half 14has been cleaned, the crank 38 may be rotated causing the unitsupporting frame 18 to be revolved and the nozzle 68 to be aligned witha lower mold surface 81 in the lower mold half 16 as shown in FIGS. 2and 3. The operation may then be repeated to clean the lower moldsurface 81.

The motor 52 is a variable speed DC motor, whereby the operator has theability to slow down the speed of rotation of hub 46 which is desirablebecause the cleaning is more efficient at slower speeds.

In order to provide air for cleaning and also provide air for therodless cylinder 78 an air line 86 in communication with a source of airunder pressure is connected to the manifold 44. A second flexible supplyline 87 in communication with a supply of frozen CO2 gas under pressureis connected to the manifold 44. A supply line 91 is provided from themanifold 44 to the nozzle 68.

Suitable controls may be provided to regulate the speed of the motor 52for rotating the hub 46 at a desired speed. These controls may also becoordinated with the controls for the rodless cylinder 78 to provide thedesired travel of the nozzle 68 radially across the mold surface 81 ofthe lower mold half 16 and mold surface of the upper mold cavity 85.

The apparatus 10 is placed in the lower mold 16 with the angle iron base20 seated in the press breech ring 21 by a fork lift 92 as shown indotted lines in FIG. 1. The upper mold half 14 is positioned directlyover the lower mold half 16. The upper mold cavity 85 may then becleaned by projecting the CO2 and air through the nozzle 68, controllingthe rotation of the nozzle by regulating the speed of the DC motor 52and regulating the movement of the nozzle 68 across the mold cavity 21by controlling the movement of the rodless cylinder 78. The crank 38 isthen locked in position and the rotation of the nozzle 68 is controlledby regulating the speed of the motor 52 for traversing circumferentiallyaround the lower mold cavity 21, and movement radially of the nozzleacross the lower mold cavity is controlled by the rodless cylinder 78.Then the upper mold 14 can be moved away from the lower mold 16 and fromthe CO2 cleaning unit 42. The CO2 cleaning unit 42 may then be liftedout of the lower mold 16 by the forklift 92 and moved to another mold inanother press without requiring any alteration of the tire presses. Asshown in FIG. 4, a sound curtain 94 is positioned around the tire moldand mold cleaning apparatus.

What is claimed is:
 1. A cleaning apparatus for cleaning the moldmounted in a tire press, said tire press having an upper mold halfpositioned over a lower mold half and movable vertically to open andclose said mold comprising: (a) a supporting frame for mounting oversaid lower mold half and under said upper mold half; (b) a rotatableframe mounted on said supporting frame for rotation about a horizontalaxis; (c) a source of frozen CO₂ (d) a nozzle for spraying said frozenCO₂ cleaning material on mold surfaces of said upper mold half and saidlower mold half said nozzle being mounted on a control arm supposed onsaid rotatable frame; (e) means to rotate said rotatable frame aboutsaid horizontal axis to move said control arm from a down position forspraying said frozen CO₂ cleaning material on said lower mold half to anup position for spraying said frozen CO₂ cleaning material on said uppermold half; and, (f) means to traverse said control arm circumferentiallyof said tire mold about a vertical mold axis wit said rotatable frame insaid down position and in said up position.
 2. The cleaning apparatus ofclaim 1 further comprising said rotatable frame having adjustablevertical legs and being supported for rotation on a shaft mounted inbearings supported an said adjustable vertical legs of said supportingframe and including means for adjusting the length of said legs toprovide the desired height of said shaft between said lower mold halfand said upper mold half.
 3. The cleaning apparatus of claim 1 furthercomprising a sound curtain positioned around said cleaning apparatus andsaid tire mold.
 4. The cleaning apparatus of claim 1 further comprisingmeans for adjusting said control arm in vertical direction toward andaway from a surface of said upper mold half and a surface of said lowermold half to maintain a predetermined distance between said nozzle andsaid surface of said upper mold half and said surface of said lower moldhalf.
 5. The cleaning apparatus of claim 1 further comprising said meansto traverse said control arm circumferentially of said tire having a hubmember mounted on said rotatable frame and supporting said control arm,said hub member being rotatable about said vertical mold axis in saiddown position and in said up position of said control arm.
 6. Thecleaning apparatus of claim 1 further comprising said cleaning materialbeing frozen CO₂ and said nozzle being in communication with said sourceof frozen CO₂ carried by air under pressure to project the spray ofcleaning material against said upper mold surface and said lower moldsurface.
 7. The cleaning apparatus of claim 4 further comprising saidmeans for adjusting the vertical position of said control arm includinga cam roller mounted on said control arm and a depth gauge membermounted on said rotatable frame having a cam slot with a cam surface forsaid cam roller.
 8. The cleaning apparatus of claim 4 further comprisingmeans for moving said control arm radially of said tire mold to traversesaid nozzle over the surface of said upper mold half and the surface ofsaid lower mold half after a predetermined circumferential traverse ofsaid control arm and said nozzle.
 9. The cleaning apparatus of claim 8further comprising a rodless piston cylinder assembly connected to saidrotatable frame and to said control arm for moving said arm in saidradial direction relative to said lower mold surface and said upper moldsurface.
 10. A method of clean a tire mold having an upper mold halfpositioned over a lower mold half and movable vertically to open andclose said mold with a portable cleaning apparatus having a supportingframe, a rotatable frame mounted on said supporting frame, a nozzle forspraying frozen CO₂ cleaning material mounted on a control arm supportedon said rotatable frame and in communication with a source said frozenCO₂ of cleaning material comprising the steps of: (a) mounting saidsupporting frame over said lower mold half; (b) rotating said frame to aposition with said control arm in an up position wherein said nozzle indirected at a mold surface of said upper mold half; (c) communicatingsaid frozen CO₂ cleaning material to said nozzle to project said fromCO₂ cleaning material against said mold surface of said upper mold half;(d) rotating said control arm to traverse said nozzle circumferentiallyof said upper mold half; (e) cleaning said mold surface of said uppermold half by spraying said frozen CO₂ cleaning material with saidnozzle; (f) rotating said rotatable frame to a position with saidcontrol arm in a down position wherein said nozzle is directed at a moldsurface of said lower mold half; (g) rotating said control arm totraverse said nozzle circumferentially of said lower mold half on saidcontrol arm for cleaning said mold surface of said lower mold half withsaid frozen CO₂ cleaning material; and, (h) removing said cleaningapparatus from said lower mold half for use in cleaning another tiremold.
 11. The method of claim 10 further comprising moving said controlarm radially of said upper mold half and said lower mold half after apredetermined circumferential traversing of said nozzle to spray saidfrozen CO₂ cleaning material over said mold surface.
 12. The method ofclaim 10 further comprising adjusting the vertical position of saidcontrol arm as said nozzle is moved radially of said upper mold half andsaid lower mold half to maintain a predetermined spacing between saidnozzle and said mold surfaces.
 13. The method of claim 10 furthercomprising communicating said frozen CO₂ cleaning material to saidnozzle and further communicating compressed air to said nozzle forspraying said frozen CO2 cleaning material on said mold surfaces. 14.The method of claim 10 further comprising traversing said nozzlecircumferentially by rotating said control arm at a vertical axis onsaid rotatable frame.
 15. The method of claim 14 comprising controllingthe speed of rotation of said frozen CO₂ control arm and the flow ofsaid cleaning material to provide cleaning of said mold surfaces as saidnozzle is traversed and further adjusting the position of said controlarm radially of said upper mold half and said lower mold half after apredetermined rotation of said nozzle about said vertical axis.